Abstract: The disclosed punching unit transforms the vertical motion of a press into a horizontal punching motion by means of two wedges inside the unit body, the down motion of the upper wedge determining the horizontal displacement of the lower wedge, the unit being provided with a return mechanism and with a locking sensor for stopping the unit. It has gas dampers or metal springs, and in one embodiment, the unit is mounted on a base plate which is larger than the plant, and which is aligned with the clamping plate, thereby providing anti-rotation in collaboration with the internal anti-rotation structure.